This invention relates to overhead ceiling fans, and more particularly to a system of mounting an overhead ceiling fan to an electrical junction box, such as may be typically installed in the ceiling of a residential room (or other room) which typically may have a ceiling height from the floor of about eight feet (2.4m.).
In recent years, overhead ceiling fans have again come into widespread use for circulating air within a room. In summer, operation of a ceiling fan will cause a gentle air flow within the room, which will substantially increase cooling and ventilation. In the winter, particularly if the fan is operated to move heated air downwardly from the ceiling, overhead ceiling fans have been found to be effective in more evenly distributing the heated air within the room, thus reducing heating requirements.
Generally, overhead ceiling fans are suspended from the ceiling by attaching them to an electrical junction box securely mounted within the ceiling. This junction box typically has power leads extending thereto for supplying conventional house current to the fan. Because of rotational imbalance loads and vibrations which may be present in the fan, it is conventional practice to hang the ceiling fan from the junction box in such manner that the fan is free, within a limited angular range, to be self-aligning with respect to the junction box thereby to allow the fan to assume its optimum operating position and to reduce or minimize stresses placed on ceilings and junction boxes. In many prior designs, the mounting of the fan to the electrical box was done by means of a J-hook, carried by the fan motor assembly, which engaged a bar carried by the electrical junction box. Typically, the J-hook was attached to a pipe extension such that the fan motor assembly extending down below the junction box a considerable distance. While these mounting systems were effective in reducing stresses, the fan's inherent tendency to wobble was increased.
To overcome this wobbling problem, ball and socket mounting systems became conventional which utilized a ball member secured to the end of the pipe extension. The ball was then socketed in a bracket carried by the electrical box such that the fan motor was free to rotate relative to the electrical box so that it was able to assume its equilibrium operating. These ball and socket mounting systems were successful in reducing wobble in that the wobble loads were damped by the friction of the ball sliding on its socket.
However, one common trait of such J-hook and prior ball and socket mounting arrangements has been the fact that an extension pipe was required between the motor assembly and the J-hook or ball member. This extension pipe posed a problem in mounting overhead ceiling fans on a residential ceiling which may, for example, have a floor-to-ceiling height of about eight feet (2.4m.). It will be appreciated that a relatively hazardous situation may be presented if the fan blades protruded below the ceiling to a level where they may come into contact with persons of average height walking under the fan. Generally, the plane of rotation of the ceiling fan blades should have a minimum height from the floor of about seven feet (2.1m.).
Heretofore, other so-called "close to the ceiling"mounting systems were commercially available, but these prior systems could not mount the fan blades sufficiently close to a residential eight-foot (2.4m.) ceiling such that at least seven feet (2.1m.) of clearance existed below the blades and such that wobbling of the fan (by means of a ball and socket mounting) was available.
Thus, there has been a long standing need for a ball swivel mounting system for an overhead ceiling fan which minimized the distance between the ceiling and the plane of rotation of the fan blades so as to maximize the distance from the floor to the fan blades.